1. Field of the Invention
The present invention relates generally to a pulverizer of a food waste treatment apparatus and, more particularly, to a pulverizing screw, a pulverizing casing and a pulverizer for a food waste treatment apparatus having the same in which the pulverizing screw has a spiral structure and the pulverizing casing has a spherical shape, and which are configured to more effectively agitate and pulverize input food waste.
2. Description of the Related Art
Generally, every house, restaurant, etc. discharges a predetermined amount of food waste everyday. Typically, such food waste is dumped after only water is removed from the food waste using a filter or the like. This conventional food waste treatment method increases the amount of food waste. If dumped food waste is not frequently treated, odors may result, with the result that the surrounding air is polluted.
To effectively reduce and recycle food waste, the development of a food waste treatment apparatus for home use which can solve the above problems is in demand. Generally, a food waste treatment apparatus which is coupled to the domestic sink of a kitchen counter removes water from food waste and reduces the volume of the food waste through a series of processes including dehydration, cutting and drying, thus reducing the amount of food waste discharged.
Food waste treatment apparatuses are classified into a variety of different kinds according to the method of treating food waste, and they are classified into a variety of different kinds according to the use thereof.
Furthermore, in conventional food waste treatment apparatuses, according to the orientation of a rotating shaft and the shape of a pulverizer, they may be classified into the vertical cylindrical type pulverizer and the horizontal cylindrical type pulverizer.
In the case of the vertical cylindrical type pulverizer, when treating food waste, a relatively low load is applied to a motor which operates a pulverizing screw to pulverize the food waste. Hence, a low-noise design can be realized. However, because the pulverizing screw is provided on the lower portion of the apparatus, food waste may not be evenly agitated or pulverized, with the result that a grain size of pulverized food waste is relatively large and food waste undesirably lumps at the central portion of the pulverizing screw and thus may not be pulverized. Furthermore, since a heater for drying food waste is provided in the lower portion of the apparatus, pulverizing and drying performance is reduced. On the other hand, the ratio of the volume occupied by the pulverizing screw is low, so that the amount of input food waste in relation to the overall size of the apparatus can be increased.
In the horizontal cylindrical type pulverizer, because a pulverizing screw for pulverizing food waste extends for the entire length of a pulverizer, food waste can be satisfactorily agitated and pulverized. Furthermore, a heater for drying food waste is provided along the cylindrical surface of the pulverizer, so that heat can be efficiently transferred to the food waste, thus increasing the efficiency of drying. However, pulverization of food waste is focused on both ends of the pulverizing screw (that is, on both ends of the pulverizer). In addition, a large quantity of food waste is compressed by the rotation of the pulverizing screw. Thereby, an overload is applied to the pulverizing screw, with the result that it may become stopped. Furthermore, there is a disadvantage in that the amount of food waste which can be input into the pulverizer is reduced because of the large volume ratio occupied by the pulverizing screw related to the volume of the pulverizer.